1. Field of the Invention
The invention pertains to vertically positioning railway switch points by utilizing the motion of two interacting comb structures.
2. Prior Art
For over 150 years switch points have moved by sliding in a horizontal plane. Throughout this long period innovation hopes have been focused on moving the switch points in a vertical plane. The virtues of vertically moving switch points include avoidance of blockage of the movement by snow, ice and debris. However, none of these vertical motion patents have resulted in a practical design that has been implemented. The designs were too weak to withstand the weights and forces experienced during typical railway operation.
In the United States, for example, weights per individual axle exceed 32 metric tons. In addition, tractive effort and braking create longitudinal forces of up to one third of the vertical force.
The advent of high speed rail operations has, strained turnout design even further, with the need to work with small acute angles and high radius switch points. The prior art could neither allow high speeds nor absorb and control such high forces.